Multiple variable air condenser



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MULTIPLE VARIABLE AR CONDENSER Filed May 1. 1926 Y, y r

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rammed Jan. 24, 192s.

CHARLES HARDY, OF NEW YORK, N. Y., ASSIGNOR TO f YORK, N. Y., A CORPORATION OF Amsco PRODUCTS, INC., or NEW YORK.

MULTIPLE VARIABLE AIR CONDENSEE.

Application led Hay 1, 1926. Serial No. 105,959.

This invention relates to electrical condensers, and more particularly to variable air condensers; and has special reference to the provision ofan improved variable air condenser of the multi-unit type designed for use in tuned radio receiving circuits for producing a uni-control or simultaneous adjustment of successive or cascaded circuits.

As is well known, for simultaneously adi justing the oscillation constants of cascaded radio frequency circuits for tuning the same in unison and to the frequency of the received Wave, it is the practice to mechanically couple the tuning control devices, such for example as the tuning condensers or inductances lin the circuits, so that these may be adjustable by the manipulation of a A'single control dial. Where condensers are employed as the tuning devices, the desired results are generally accomplished either by mechanically coupling the rotor shafts of separate condensers or by building the condenser units in a single assembly with the rotois of the units mounted on a single shaft. In either form of construction it is an important desideratum to balance and equalize the tuning devices with great precision and accuracy throughout the whole tunin range so that the oscillation constants of t e cascaded circuits may be adjusted to the same value with optimum precision throughout the wave length range for which the system istunable.

To equalize the tuning operations, the condensers must be carefully matched or bal-V 1 anced so that the calibration curves of the v and assembled by the same, especially when the condensers are in connected circuit arrangement, are` Substantially identical. Considerable diiiiculty has been experienced in producing an 'exact match or equalization of the condenser units to meet the usual service requirements, in spite of the fact that the condensers are car pable of being standardized and built with suiicient precision by present manufacturing methods. It has been found, for eX- ample, that even though the condenser units which are coupled together for simultaneous adjustment or uui-control are adjusted manufacturer so that a balance is obtained, the balance or equalization of the condenser units will notv be maintained under service conditions, due

generally to a structural `.instability of the condenser assembly. I have found that such instability arises from inherent mechanical forces and stresses active on the condenser parts to alter or distort the same and vary the capacities of the respective condenser umts, especially when such condenser units are built or stacked up in a single assembly. I have further found that these forces and stresses may be mechanically balanced and counteracted so that the structural instability of the built-up assembly is eectively inhibited, so much so that the condenser units when once matched or balanced by the manufacturer will remain and will be maintained in balanced relation in normal use, even for an extended period of time.

The prime desideratum of my present invention therefore comprehends the provision of a multiple variable condenser in which the aforesaid disadvantages incident to condensers of prior manufacture are overcome and inzwhich means are provided for counteracting or neutralizing such forces and stresses which have been found to produce distorting' tendencies and consequent structural and electrical instability of the condenser. y

To the accomplishment of the foregoing and suchother objects as will hereinafter appear, my invention consists in the ele-A ments and their relation one to the other, as hereinafter more particularly described and sought to be defined in the claims; reference being had to the accompanying drawings which showV the preferred embodiments of my invention, and in which:

Fig. 1 is a side elevational view of one form of multiple variable air condenser with parts broken away and showing my in vetion applied thereto,

Fig. 2 is a rear end elevational View thereof, v

Fig. .3 is a view thereof taken in crosssection lin the plane of the line 3 3, Fig.l l.

Fig. 4 is a vertical elevational view of a modified form of multiple condenser showing my invention applied thereto, and

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Fig. 5 is a view thereof taken in cross-seccondenser comprising a frame structure genl erally designated as and a plurality of vcondenser units generall designated as C',

C2 and C3 mounted in uilt-up or stacked relation on the frame structure F, each of the condenser units'including a statorV and a rotor plate set designated respectively byV s and 7' with an exponent corresponding to 'the condenser unit of which it forms a part.

washers 17, 17 being preferably interposed' between the securing nuts and the end plates. The other connecting members 12-14 embody slmilar parts which are designated by corresponding and similar ref-v erence characters. s Where the condenser embodies triple condenser units the frame F preferably further includes a backing or supporting plate 18 to which the end plates 10 and 11 are joined by means of the angle brackets 19 and 20 secured to the backing l plate 18 by means of the attaching elements -21, 21, the said angle brackets being joined to the end plates 10 and 11 by attachment to the connecting( rods 14 and 15, as clearly shown in the drawings.

The rotor plate sets 1", r2 and r3 each comprises a plurality of condenser lplates 22, 22 all affixed in spaced relation to a single rotor shaft 23, whichXshaft is journalled for rotation in the end plates 10 and 11 of the frame F. In the preferred construction the plates are 4secured -to the rotor'shaft in a manner disclosed in my copending application to electrical condenser manufacture, Serial No. 74,471, filed Dec. 10, 1925.

The Vstator plate sets s', s2 and .s3 each comprises a plurality of condenser plates 24, 24 arranged in interleaving relation with the stator plates 22, 22, the stator plates of the stator unitss, s2 and s3 being carried respectively by the posts 25, 26 and 27, which are insulatably mounted from each other ap'd from the frame F. For insulatably mounting the stators on the frame. there are provided at each end of the condenser assembly a plurality of 'insulating members 28, 28, which in theV preferred construction comprises tubular units, as clearly shown in 1 of the drawings, one end of the tu- Fi ,buar units being seated in cup-shaped elements 29, 29 eyeleted or riveted to the end plates, the other end of each of the tubular units being provided with a flanged cap 30 centrally apertured to receive a stud portion 31 integral with the stator supporting posts such as the post 27 illustrated in Fig. 1 of the drawings, this construction being provided so that the stator units may be Lacasse mounted during assembly on the insulating pieces to interlock with the same w1thout the use or employment of securing elements.

The stator plate sets s', s2 and s3 are in-l sulatably supported from each other by means which include elements interposed between the stator plate sets and eHective for mutually supporting one plate set longitudinally on the other, such means comprising the insulating members 32, 32 interposed between the adjacent ends of the stator posts 25-27, and in the preferred construction each of the insulating members is recessed at the opposite ends thereof for receiving the contiguousends of the stator posts. In the preferred construction each of these -insulating members comprises a tubular unitv as shown in Fig. 1 of the drawings, each end of which receives a pin or stud portion 33 integral with a stator post, a flanged or cup-shaped recessed element 34 being recelved by the stud portion and inter osed so as to seat the end of its tubular unit 32. With this/construction it will be seen that the stator units may e stacked up or built in longitudinal alignment and may be assembled one with respect to the other by merely interlocking the insulating members with the stator supporting posts, the assembling of the Parts being` obtained with' facility and without the use of securing ele,- ments such as screws or bolts.

This multiple condenser assembly is Iparticularly designed for use in radio receiving circuits as a uni-tuning control for the cas! caded radio frequency circuits thereof, and as heretofore explained, the rotor and stator components of the condenser units must be carefully balanced and mechanically matched so that the capacities thereof may be equalized over the whole tuning range of the radio receiving set. As heretofore stated, it has been found that even though the -condenser units are adjusted and assembled by the manufacturer so that a balance is, obtained, the balance or equalization of the condenser units will be disturbed under service conditions. I have found that this is due generally to a structural instaixa porting elements and the gravitational effect v on the stator parts both tend to distort or alter the position of the stator posts and the insulating members interposed therebetween, this resulting in moving the stator and rotor plates out of true parallel relation, the uneven distortion producing an -undesirable mis-matching of the condenser units.

I have found that these compressive and gravitational forces and stresses may be efl fectively compensated for and counter-acted service conditions.

yersely supporting the stators in a region; intermediate the end plates of the condensers and preferably such means is designed and constructed vto support the stators on the condenser frame to produce a transverse mutual support for the frame and stator parts. l

More specifically, such means comprises the plate-shaped members 35. 35 arranged intermediate adjacent condenser units such as the units C and C2 or Czand C3, said plate-shaped members connecting so 'as to mechanically join together for transverse support the frame members 12-15 with the interposed stator supporting-elements 32.l 32,-

the construction being such that the stator supporting elements and the stator units supported thereby are held against transverse displacement in regions intermediate the end plates 10 and 11 of the frame F.

. The plateeshaped members 35. are tired `to the frame members 12'-15so as to mutually support one frame member with respect to the other transversely, and are connected to the interposed stator supporting elements 32, 32 to support the latter transversely but not longitudinally so that relative longitudinal movement is permitted while transverse movement is prevented, this afording greater facility in assembling the parts and permitting differential expansion and contraction in a longitudinal direction between the parts.

Structurally each of the plate-shaped members 35 is fixed to minal apertures 35', 35', (Fig. 3) received by the connecting frame rods 12-15 and ing, however, capable of longitudinal movement `in the members ,Specied By means of this construction I not only accomplish the important results of transversely joining the stators to the condenser 35 for the ,purpose a plurality of frame' members, the same being provided ,with ter-- frame at intermediate regions and to strengthen the connecting frame members at such regions, but I am enabled to provide an assembly in which the compressive stresses exerted on the aligned stator posts 25-27 by the end'plates are efectively minimized or eliminated, such compressive stresses being wholly undesirable in a condenser assembly. It will be seen, moreover, that the mechanism provided is comparatively simple and is so designed as to permit the ease of assembling of the condenser parts which characterizes the condenser construction.

Referring now to Figs. 4 and 5 of the drawings, I show my invention yapplied in its preferred form to a double condenser of the straight-line frequency type, such condenser differing from that shown in Figs. 1-3 of the drawings principally by the shape of the plates and the manner of supporting the stator in the condenser frame. The parts, otherwise similar, are designated by similar reference characters.

In the modified form of the invention as shown in Figs. 4 and 5, the plates 10 and 11 of the frame F are connected together by means of three frame rods 37, 38 and 39 having the spacing sleeves 40, 40 thereon, the supporting posts 25 and 26 for the stators s and s2 being arranged in a longitudinal plane intersecting the longitudinal plane passing through the connectingrods 37 and 38, as clearly shown in Fig. 5 of the drawings. For transversely supporting the stator insulating elements 32, 32 (two in number) on the frame members 37 and 38, I preferably provide -a single plate-shaped member 41 arranged intermediate the condenser units C and C2, the said plate-shaped member 41 being fixed to the frame rods 37-39 between the spacing sleeves 40 and being recessed at 42, 42 for slidably yet snugly receiving the insulating members or elements 32, 32 in a manner similar to that described in connection with Figs. 1-3 of thedrawings. In this modified formof the invention, the plates ofthe rotor units 7" and r2 may be connected together by means of a strap or connecting plate 43 whichv bridges the member 41.

The manner of assembling and using the multiple variable air condenser of my present invention and the advantages thereof will in the main be fully apparent from the above vdetailed description and operation thereo.

It will be further apparent that While I have shown and described my invention in the preferred forms, many changes and modifications may be made in the construction disclosed without departing from the spirit of the invention, defined in the following claims.

1. A multiple variable condenser com rising a frame yhaving end plates and mem rs connecting the end plates, a rotor journalled in said frame and'having a plurality of rotor plate sets, a stator mounted in said frame and having a plurality of stator plate sets arranged to interleave with the rotor plate sets to orm therewith a plurality of condenser units, means for insulating the statorv plate sets from each other including elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally on the other, and means arranged intermediate the condenser units connecting so as to mechanically join to- 'gether the frame members with said interposed stator supporting elements :for transversely supporting the frame andthe stator E in a region intermediate the end plates.'

2. A multiple variable condenser comprising a frame having end plates and members connecting the end plates, a rotor journalled' with an interposed stator supporting element for transversely supporting the stator on the :trame and .one frame member on the other in a regionv intermediate the end plates.

3. A multiple variable condenser A comprising a frame having end plates and members connecting the end plates, a rotor journalled in said frame and having a plurality of rotor plate sets', a-stator mounted in said frame and having a plurality of stator. plate sets arranged to interleave with the rotor plate sets to orm therewith a lplurality of condenser units, elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally on the other, and means arranged intermediate the condenser units connecting so as to mechanically join thek frame members with said interposed stator supporting elements for transversely supporting the frame and the stator in a region intermediate the end plates. Y

4. A multiple variable condenser comprising a frame having endiplates and members connecting the end plates, a rotor journalled in said frame and having a lurality of rotor plate sets, a stator mounte in said frame and having a plurality of stator plate sets arranged tointerleave withv the rotor plate sets-to form therewith a `plurality of condenser units, elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally on the other, and means arranged intermediate the condenserunits fixed to and mechanically joining a plurality of the frame members and effective for transversely supporting the frame members one on the other, said means being connected4 to said interposed stator supporting elements so asto prevent transverse movement while permitting longitudinal movement between the said intei-posed elements and frame members.

5. A multiple variable condenser comprising a frame having metallic end plates and members connecting the'end plates, a rotor journalled in and conductively connected Vto said frame and having a plurality of rotor plate sets, a stator insulatably mounted in said frame and having a plurality ofstator plate sets arranged to interleave with the rotor plate sets to form therewith a plurality of condenser units, means for insulating the stator plate sets from each other including insulating elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally on the other, and means arranged intermediate the condenser units mechanically joining a plurality of frame members together and to said interposed stator supporting insulating elements for transversely and mutually supporting the frame members and the stator in a region intermediate the end plates.

6. A multiple variable condenser comprising a frame having end plates and members connecting the end plates, a rotor journalled in said frame and having a plurality of rotor plate sets, a stator mounted in said frame and having a plurality of stator plate sets arranged to interleave with the rotor plate sets to form therewith a plurality of condenser units, elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally 0n the other, and a means iixed to and transversely joining the frame members at a region intermediate the condenser units, said means embracing an interposed stator supporting 'element for supporting thesame transversely on the frame members.

7. A multiple variable condenser compris- 'ing a frame having end plates and members connecting the end plates, a .rotor journalle'd in said frame and having a plurality of rotor plate sets, a stator mounted in said frame and having a plurality of stator plate sets arranged to interleave with the rotor plate sets to form therewith aplurality of con-v denser units, elementsV interposed between the said stator plate sets andmutually supporting .one plate set longitudinally on the other, a plurality of said vframe members each including a rod and spacing sleeves thereon, anda plate shaped means fixed to the frame members between the spacing sleeves thereof and transversely joining the frame members for mutual support, the said plate shaped means having an orifice supportingly receiving a stator supporting element.

8. A multiple variable condenser comprising a frame having metallic end plates and a plurality of members connecting the end plates, a rotor conductively journalled in said frame and having a plurality of rotor plate sets, a stator insulatably mounted in said frame and having a plurality of stator l plate sets arranged to interleave with the rotor plate sets to form therewith a plurality of condenser units, insulating elements interposed between the said stator plate sets and mutually supporting one plate set longitudinally on the other, the said frame members each including a connecting rod and spacing sleeves thereon, and -plate shaped means iixed to a plurality of said rods between the spacing sleeves thereof for transversely joining the frame members for mutual support, the said plate shaped means having an orifice receiving an insulating element for transversely supporting the same and the stator on the frame members.

9. A multiple variable condenser comprising a rotor plate set, metallic end supporting plates conductively integral therewith, members connecting the end supporting plates, a plurality of stator plate sets, means for supporting the stator plate sets insulated from each other and from the end supporting plates, said means consisting of a plurality of posts carrying each stator plate set, insuating members arranged between the posts of the stator plate sets and insulating pieces arranged between the end supporting plates and the adjacent ends of the said posts of the stator plate sets, and means arranged intermedia-te the stator plate sets connecting so as to mechanically join together a plurality of the said members with the said insulating members for providing mutual transverse support between the stator plate sets and the said members.

Signed at New York city in the county of New York and State of New York this 23rd day of April A. D. 1926.

CHARLES HARDY. 

